scholarly journals The CP violation and scalar dark matter in a 331 model

2021 ◽  
Vol 36 (09) ◽  
pp. 2150057
Author(s):  
M. J. Neves

The 331 model with right-handed neutrinos is reassessed to investigate the CP violation in the quark sector. After the spontaneous symmetry breaking, the masses and physical fields of the particle content are obtained. The fermions content of the 331 model is enlarged to include exotic quarks with known electric charge and with masses defined at the TeV scale. The existence of these exotic quarks induces extra CP violations via couplings with quarks of the Standard Model mediated by charged gauge boson with mass fixed at the TeV scale. An extra discrete [Formula: see text] symmetry is introduced in the 331 model to get a stable scalar field that can be a candidate to the dark matter content. The new scalar field interacts at the tree level with the [Formula: see text] gauge boson that works as a dark matter portal. The relic density associated with the scalar field is calculated to yield the solution mass that satisfies the observed dark matter. The region allowed on the parameter space of the dark matter mass versus [Formula: see text] mass is obtained to include the bounds of PANDAX2017, XENON1T(2t.y) and LUX experiments.

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Eung Jin Chun ◽  
Arnab Dasgupta ◽  
Sin Kyu Kang

Abstract We propose a novel mechanism to realize leptogenesis through the Breit- Wigner resonance of a dark U(1)D gauge boson ZD , which mediates lepton number vi- olating annihilations of dark matter (DM) in the context of the scotogenic model with a U(1)D . The processes occur out of equilibrium and DM freezes out later giving rise to the observed abundance. The CP violation required for leptogenesis can be achieved by the interference between tree-level t-channel scattering of DM and the subsequent 1-loop mediated by ZD , which arises due to the unremovable imaginary part of either the ZD propagator coming from its self-energy correction or the 1-loop giving rise to the effective coupling of $$ {Z}_D\overline{\nu}\nu $$ Z D ν ¯ ν .


2022 ◽  
Vol 82 (1) ◽  
Author(s):  
Salvatore Bottaro ◽  
Dario Buttazzo ◽  
Marco Costa ◽  
Roberto Franceschini ◽  
Paolo Panci ◽  
...  

AbstractWe study scenarios where Dark Matter is a weakly interacting particle (WIMP) embedded in an ElectroWeak multiplet. In particular, we consider real SU(2) representations with zero hypercharge, that automatically avoid direct detection constraints from tree-level Z-exchange. We compute for the first time all the calculable thermal masses for scalar and fermionic WIMPs, including Sommerfeld enhancement and bound states formation at leading order in gauge boson exchange and emission. WIMP masses of few hundred TeV are shown to be compatible both with s-wave unitarity of the annihilation cross-section, and perturbativity. We also provide theory uncertainties on the masses for all multiplets, which are shown to be significant for large SU(2) multiplets. We then outline a strategy to probe these scenarios at future experiments. Electroweak 3-plets and 5-plets have masses up to about 16 TeV and can efficiently be probed at a high energy muon collider. We study various experimental signatures, such as single and double gauge boson emission with missing energy, and disappearing tracks, and determine the collider energy and luminosity required to probe the thermal Dark Matter masses. Larger multiplets are out of reach of any realistic future collider, but can be tested in future $$\gamma $$ γ -ray telescopes and possibly in large-exposure liquid Xenon experiments.


2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Isabell Engeln ◽  
Pedro Ferreira ◽  
M. Margarete Mühlleitner ◽  
Rui Santos ◽  
Jonas Wittbrodt

Abstract We discuss the dark phases of the Next-to-2-Higgs Doublet model. The model is an extension of the Standard Model with an extra doublet and an extra singlet that has four distinct CP-conserving phases, three of which provide dark matter candidates. We discuss in detail the vacuum structure of the different phases and the issue of stability at tree-level of each phase. Taking into account the most relevant experimental and theoretical constraints, we found that there are combinations of measurements at the Large Hadron Collider that could single out a specific phase. The measurement of h125 → γγ together with the discovery of a new scalar with specific rates to τ+τ− or γγ could exclude some phases and point to a specific phase.


2013 ◽  
Vol 53 (A) ◽  
pp. 528-533
Author(s):  
Giulio Auriemma

The most interesting cosmological open problems, baryon asymmetry, dark matter, inflation and dark energy, are not explained by the standard model of particle physics (SM). The final<br />goal of the Large Hadron Collider an experimental verification of the SM in the Higgs sector, and also a search for evidence of new physics beyond it. In this paper we will report some of the results obtained in 2010 and 2011, from the LHCb experiment dedicated to the study of CP violations and rare decays of heavy quarks.


2018 ◽  
Vol 168 ◽  
pp. 06002
Author(s):  
Aditya Aravind ◽  
Minglei Xiao ◽  
Jiang-Hao Yu

We discuss the inflationary model presented in [1], involving a gauge singlet scalar field and fermionic dark matter added to the standard model. Either the Higgs or the singlet scalar could play the role of the inflaton, and slow roll is realized through its non-minimal coupling to gravity. The effective scalar potential is stabilized by the mixing between the scalars as well as the coupling with the fermionic field. Mixing of the two scalars also provides a portal to dark matter. Constraints on the model come from perturbativity and stability, collider searches and dark matter constraints and impose a constraining relationship on the masses of dark matter and scalar fields. Inflationary predictions are generically consistent with current Planck data.


Author(s):  
V. Zhdanov ◽  
A. Alexandrov ◽  
O. Stashko

We consider a homogeneous isotropic Universe filled with cold matter (with zero pressure) and dynamic dark energy in a form of a scalar field. For known scalar field potential V(φ), the Friedmann equations are reduced to a system of the first order equation for the Hubble parameter H(z) and the second order equation for the scalar field as functions of the redshift z. On the other hand, knowledge of H(z) allows us to get the scalar field potential in a parametric form for a known cold matter content and three dimensional curvature parameter. We analyze when the accepted model mimics the dependence H(z) derived in the framework of the other models, e.g., hydrodynamic ones. Two examples of this mimicry are considered. The first one deals with the case when H2(z)~ Ωm(1+z)3+ΩΛ, but Ωm parameter overestimates the input of the cold matter (dark matter+baryons). The resulting scalar field potential is V(φ)=a+bsinh2(cφ), where the constants a,b,c depend on the Ω – parameters of the problem. In the other example we assume that some part of the dark matter has a non-zero equation of state p=wε, -1<w<1. In this case H2(z)~ Ωdm1(1+z)3(1+w)+ Ωb+Ωdm2)(1+z)3+ΩΛ. The corresponding potentials are defined for positive values of φ. For both signs of w potential V(φ) is a monotonically increasing function with typically an asymptotically exponential behavior; though for some choice of parameters we may have a singularity of V(φ)on a finite interval. Then we consider fitting of the potential for w from the interval [-0.2,0.2] for three different values of Ωdm2 by means of a simple formula Vfit(φ)=p0+p1exp(p2 φ). The dependencies pi(w) are presented and the approximation error is estimated.


2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Andrey Katz ◽  
Ennio Salvioni ◽  
Bibhushan Shakya

Abstract We discuss a minimal realization of the strongly interacting massive particle (SIMP) framework. The model includes a dark copy of QCD with three colors and three light flavors. A massive dark photon, kinetically mixed with the Standard Model hypercharge, maintains kinetic equilibrium between the dark and visible sectors. One of the dark mesons is necessarily unstable but long-lived, with potential impact on CMB observables. We show that an approximate “isospin” symmetry acting on the down-type quarks is an essential ingredient of the model. This symmetry stabilizes the dark matter and allows to split sufficiently the masses of the other states to suppress strongly their relic abundances. We discuss for the first time the SIMP cosmology with sizable mass splittings between all meson multiplets. We demonstrate that the SIMP mechanism remains efficient in setting the dark matter relic density, while CMB constraints on unstable relics can be robustly avoided. We also consider the phenomenological consequences of isospin breaking, including dark matter decay. Cosmological, astrophysical, and terrestrial probes are combined into a global picture of the parameter space. In addition, we outline an ultraviolet completion in the context of neutral naturalness, where confinement at the GeV scale is generic. We emphasize the general applicability of several novel features of the SIMP mechanism that we discuss here.


2009 ◽  
Vol 24 (18n19) ◽  
pp. 3366-3371 ◽  
Author(s):  
W-Y. PAUCHY HWANG

These days we learn that, in our Universe, the dark matter occupies about 25% of the content, compared to only 5% of the "visible" ordinary matter. We propose that the description of the dark matter would be an extension of the Standard Model - a gauge theory. We all know that in the Standard Model we have three generations but still don't know why - the so-called "family problem". On other hand, in view of the masses and oscillations, the neutrinos now present some basic difficulty in the Standard Model. In this note, I propose that on top of the SUc(3)×, SU(2) × U(1) standard model there is an SUf(3) extension - a simple SUc(3) × SU(2) × U(1) × SUf(3) extended standard model. The family gauge bosons (familons) are massive through the so-called "colored" Higgs mechanism while the remaining Higgs particles are also massive. The three neutrinos, the electron-like, muon-like, and tao-like neutrinos, form the basic family triplets. Hopefully all the couplings to the "visible" matter are through the neutrinos, explaining why the dark matter is more than the visible matter in our Universe.


2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Raffaele Tito D’Agnolo ◽  
Di Liu ◽  
Joshua T. Ruderman ◽  
Po-Jen Wang

Abstract We present kinematically forbidden dark matter annihilations into Standard Model leptons. This mechanism precisely selects the dark matter mass that gives the observed relic abundance. This is qualitatively different from existing models of thermal dark matter, where fixing the relic density typically leaves open orders of magnitude of viable dark matter masses. Forbidden annihilations require the dark matter to be close in mass to the particles that dominate its annihilation rate. We show examples where the dark matter mass is close to the muon mass, the tau mass, or the average of the tau and muon masses. We find that most of the relevant parameter space can be covered by the next generation of proposed beam-dump experiments and future high-luminosity electron positron colliders. Forbidden dark matter predicts large couplings to the Standard Model that can explain the observed value of (g − 2)μ.


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